Question: 57 days late on my period 3 faint positives 1 negative. Could I be pregnant.

Okay, so I have Hypothyroidism, some people say I can still conceive. My husband and I have been trying for almost two years now, about 4 days ago I took a HPT in the morning which had a very very faint line show up a minute later. Then the next morning I took another one, exactly the same thing happened. I thought maybe they were defected, so asked my husband to buy me two more, I took one at around 10 pm and it was completely negative, but then I took the last one in the morning and it came back positive again... I'm so confused cause the lines are so light, you have to really pay attention to it. But a month ago I took like 6 and they were all completely negative. Since my period is not regular I have no idea when I could have conceived if I am pregnant. I need help, has anyone gone through this? I want to be sure before I waste my time at a doctor's office.